Recently, semiconductor devices have been manufactured in small lots and various types of products. When semiconductor devices are manufactured in small lots and various types of the products, it is required to improve the productivity. As one method that satisfies this requirement, there is a method for improving the productivity of a substrate processing system such as a single substrate processing apparatus including a plurality of process chambers.
However, the productivity may be reduced by the mismatch between the number of process chambers installed in the substrate processing system and the number of substrates to be processed.